US20240078895A1 - Optical filter, and test assembly and method for smoke detector - Google Patents

Optical filter, and test assembly and method for smoke detector Download PDF

Info

Publication number
US20240078895A1
US20240078895A1 US18/308,002 US202318308002A US2024078895A1 US 20240078895 A1 US20240078895 A1 US 20240078895A1 US 202318308002 A US202318308002 A US 202318308002A US 2024078895 A1 US2024078895 A1 US 2024078895A1
Authority
US
United States
Prior art keywords
light
optical filter
screen
smoke detector
wires
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
US18/308,002
Other languages
English (en)
Inventor
Maoqing Yang
Jialin ZHANG
Dachuan WANG
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carrier Corp
Original Assignee
Carrier Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Carrier Corp filed Critical Carrier Corp
Publication of US20240078895A1 publication Critical patent/US20240078895A1/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0231—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures the surface having microprismatic or micropyramidal shape
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
    • G08B29/12—Checking intermittently signalling or alarm systems
    • G08B29/14—Checking intermittently signalling or alarm systems checking the detection circuits
    • G08B29/145—Checking intermittently signalling or alarm systems checking the detection circuits of fire detection circuits
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/208—Filters for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/103—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation

Definitions

  • the present invention relates to the field of smoke detectors, in particular to an optical filter, and a test assembly and method for smoke detector for use in smoke detector testing.
  • Smoke detectors are used to detect smoke and fire. Common smoke detectors include ion smoke detectors, photoelectric smoke detectors and infrared beam smoke detectors. Infrared beam smoke detection is a fire detector which responds to the flue gas parameters around a linear narrow region within the detecting area. It mainly differs from the previous two kinds of point smoke detectors in that the light beam transmitter of the linear smoke detector emits light to the detecting area, and the photoelectric receiver receives the light beam from the detecting area and detects smoke based on the attenuation of the light beam.
  • Infrared beam smoke detectors are divided into two types: opposite beam smoke detectors and reflective smoke detectors, wherein in a reflective smoke detector, the light beam transmitter and the photoelectric receiver are arranged on the same side while a reflector is arranged on the opposite side.
  • a reflective smoke detector the light beam transmitter and the photoelectric receiver are arranged on the same side while a reflector is arranged on the opposite side.
  • the object of the present application is to solve or at least alleviate the problems existing in the prior art.
  • an optical filter for testing of a smoke detector which comprises: a support; and a screen supported by the support, wherein the screen is composed of wires and mesh holes are defined between the wires, and the screen has s first side and a second side opposite to each other; wherein, the smoke detector comprises a light transmitter and a light receiver arranged in vicinity and an light reflector arranged opposite to the light transmitter and the light receiver, such that light emitted by the light transmitter is reflected to the light receiver via the light reflector; and wherein, during testing, the optical filter is arranged in both the light path from the light transmitter to the light reflector and the light path from the light reflector to the light receiver, where at least the side of the wires of the screen facing the light transmitter of the smoke detector is convex so as to attenuate or eliminate light directly reflected back to the light receiver by the optical filter.
  • both sides of the wires of the screen are convex.
  • the support is a frame surrounding the screen.
  • a cross section of the wires of the screen is circular, elliptical, square, triangular, pentagonal, hexagonal, heptagonal or octagonal, or of any other suitable shape.
  • the wires of the screen define mesh holes of a triangular, square, diamond or hexagonal shape, or any other suitable shape.
  • the wires of the screen are made of plastic or metal.
  • the wires of the screen are made of nylon.
  • the wires of the screen are braided, bonded or inserted into the support.
  • the optical filter for testing of a smoke detector, is integrally moulded with plastic.
  • a test assembly for a smoke detector which comprises: a smoke detector comprising a light transmitter and a light receiver arranged in vicinity and a light reflector arranged opposite to the light transmitter and the light receiver, such that light emitted by the light transmitter is reflected to the light receiver via the light reflector; and the optical filter according to the various embodiments.
  • a test method for a smoke detector comprises: arranging the optical filter according to the various embodiments in a light path from a light transmitter to the light reflector and a light path from the light reflector to the light receiver of the smoke detector, at a distance of more than 0.5 meter from the light transmitter.
  • the device and method according to the embodiments of the present invention may accurately test a smoke detector.
  • FIG. 1 shows a structural schematic diagram of a smoke detector according to an embodiment of the present invention
  • FIG. 2 shows a schematic diagram of an optical filter for a smoke detector according to an embodiment of the present invention
  • FIGS. 3 and 4 show partial enlarged views of optical filters for a smoke detector according to an embodiment of the present invention
  • FIG. 5 shows cross-sectional views of the wires of screens of optical filters according to an embodiment of the present invention
  • FIG. 6 shows schematic diagrams of light reflections from screen wires of various cross-sectional shapes
  • FIG. 7 shows schematic diagrams of screen holes of screens of an optical filter according to an embodiment of the present invention.
  • a smoke detector specifically a reflective infrared beam smoke detector
  • the smoke detector comprises: a light transmitter 21 and a light receiver 22 arranged in vicinity.
  • the light transmitter 21 and the light receiver 22 can, for example, be integrated in the same housing 2 and mounted at a certain height on the wall of a building through a mounting support 1 .
  • a light reflector 4 is arranged on the wall opposite to the light transmitter 21 and the light receiver 22 , so that light emitted by the light transmitter 21 passes through a light path 51 , is reflected by the light reflector 4 , passes through a light path 52 , and then comes to the light receiver 22 .
  • the light can be infrared beam, which is not to be seen by human eyes, and the distance between the two walls can reach up to 100 meters, thus detecting a relatively large indoor space.
  • the light intensity received by the light receiver 22 decreases, thereby causing the smoke detector to sound an alarm.
  • the light receiver 22 will not receive the light at all, and the smoke detector will report an error after a short alarm.
  • the smoke detector shown in FIG. 1 needs to be tested for proper operation after it is installed in a building or after a certain period of time.
  • One of the testing methods is that an optical filter 3 is arranged in both the path 51 from the light transmitter 21 to the light reflector 4 and the path 52 from the light reflector 4 to the light receiver 22 at the time of testing, where the optical filter 3 attenuates the light that is reflected back to the light receiver 22 and thus triggers the smoke detector to sound an alarm.
  • the existing optical filters that are made by coating black color on transparent materials or by opening holes on blocking materials have a flat surface facing the light transmitter 21 , part of the light will be directly reflected back to the light receiver 22 by the optical filter 3 , where the light superimposes onto the light reflected back to the light receiver 22 via the light reflector 4 , thus reducing the reliability of the test results and even in some cases leading to failure of sounding an alarm from the smoke detector.
  • the smoke detector is in normal operation then.
  • FIGS. 2 to 4 show an optical filter according to an embodiment of the present invention.
  • the optical filter 3 comprises: a support 30 ; a screen 31 supported by the support 30 .
  • the screen 31 is composed of wires 32 and mesh holes 33 are defined between the wires 32 .
  • the screen 31 has a first side and a second side opposite to each other.
  • the optical filter 3 is arranged in both the light path 51 from the light transmitter 21 to the light reflector 4 and the light path 52 from the light reflector 4 to the light receiver 22 , and is substantially perpendicular to the light paths 51 , 52 . It should be understood that, in practice, the light paths 51 , 52 are substantially parallel to each other.
  • the light paths 51 , 52 are depicted to have a relatively large angle for clarity purposes.
  • at least the side of the wires 32 of the screen 31 that faces the light transmitter 21 of the smoke detector is convex so as to attenuate or eliminate the light directly reflected back to the light receiver by the optical filter 3 .
  • the embodiments of the present application enable light reflected by the wires 32 of the screen 31 to scatter around without interfering with the testing.
  • the wires 32 of the screen 31 of the optical filter has a convex shape on one side, at which point it is necessary to make this side face the light transmitter 21 during testing.
  • the wires 32 of the screen 31 of the optical filter are convex on both sides.
  • the support 30 is a frame surrounding the screen 31 .
  • the support 30 may be arranged only on some edges of the screen.
  • the support 30 can be of suitable width to provide sufficient support for the screen so as to ensure its strength.
  • the arrangement of a support 30 facilitates hand-held testing by the tester.
  • the support 30 may include a handle part to be hold by the tester to further facilitate hand-held testing by the tester.
  • the support 30 may include a connecting part to connect to various test machines.
  • the cross section of the wires 32 of the screen 31 may be circular as shown in 302 of FIG. 5 , or elliptical as shown in 305 of FIG. 5 , or square as shown in 303 of FIG. 5 (where one corner of the square, instead of a plane, faces the light transmitter), or triangular (not shown), or pentagonal as shown in 306 of FIG. 5 , or hexagonal as shown in 307 of FIG. 5 , or heptagonal as shown in 308 of FIG. 5 , or octagonal (not shown), while maintaining a convex shape on the side facing the light transmitter.
  • FIG. 5 As can be seen from FIG.
  • the reflected light when the plane shown in 301 is used, the reflected light is in the opposite direction to the incident light, and the reflected light superimposes onto the returned light beam reflected by the reflector 4 into the light receiver, thereby causing interference.
  • the circular cross section 302 , the square cross section 303 or the polygonal cross section 304 when used, the reflected light scatters sufficiently so as not to interfere with the detection.
  • the mesh holes may be triangular as shown in 331 , square as shown in 332 , diamond-shaped as shown in 333 , hexagonal as shown in 334 , or of any other suitable shape.
  • the size of the mesh hole can be configured according to the requirements of the actual test.
  • wires 32 of the screen 31 can be made of plastic or metal.
  • the support 30 can also be made of plastic or metal.
  • the support 30 and the screen can be integrally formed, e.g., by moulding with plastic.
  • the support 30 can be moulded separately with threading holes formed thereon, so that the wires 32 of the screen 31 can be braided around the support 30 . In this way, different sizes of mesh holes can be achieved without multiple moulds.
  • the screen 31 can also be bonded or inserted into the support 30 , or mounted to the support 30 in any suitable manner.
  • the wires 32 of the screen 31 can be made of nylon, the thickness of which can be adjusted according to actual requirements.
  • a test assembly for a smoke detector which comprises: a smoke detector comprising a light transmitter and a light receiver arranged in vicinity, and a light reflector arranged opposite to the light transmitter and the light receiver, so that the light emitted by the light transmitter is reflected to the light receiver via the light reflector; and an optical filter according to the various embodiments.
  • a test method for a smoke detector comprises: arranging the optical filter according to the various embodiments in a light path from the light transmitter to the light reflector and a light path from the light reflector to the light receiver of the smoke detector, at a distance of more than 0.5 m from the light transmitter.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Business, Economics & Management (AREA)
  • Analytical Chemistry (AREA)
  • Emergency Management (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Chemical & Material Sciences (AREA)
  • Fire-Detection Mechanisms (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
US18/308,002 2022-04-28 2023-04-27 Optical filter, and test assembly and method for smoke detector Pending US20240078895A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210458515.0A CN117008231A (zh) 2022-04-28 2022-04-28 滤光器、烟雾探测器测试组件和测试方法
CN202210458515.0 2022-04-28

Publications (1)

Publication Number Publication Date
US20240078895A1 true US20240078895A1 (en) 2024-03-07

Family

ID=86272216

Family Applications (1)

Application Number Title Priority Date Filing Date
US18/308,002 Pending US20240078895A1 (en) 2022-04-28 2023-04-27 Optical filter, and test assembly and method for smoke detector

Country Status (3)

Country Link
US (1) US20240078895A1 (zh)
EP (1) EP4270350A1 (zh)
CN (1) CN117008231A (zh)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6822216B2 (en) * 2002-01-08 2004-11-23 Honeywell International, Inc. Obscuration detector
JP6168726B2 (ja) * 2012-02-21 2017-07-26 日本信号株式会社 光学フィルタ

Also Published As

Publication number Publication date
EP4270350A1 (en) 2023-11-01
CN117008231A (zh) 2023-11-07

Similar Documents

Publication Publication Date Title
JP4347296B2 (ja) 散乱光式煙感知器
TWI483218B (zh) Photoelectric smoke detectors
US20230384218A1 (en) Fire detection device
US5642099A (en) Light scattering type smoke detector
JP7392075B2 (ja) 煙感知器
CN113269944A (zh) 烟雾探测器
JP6905900B2 (ja) 散乱光式感知器
JPH08166347A (ja) 光電式煙感知器
PL184244B1 (pl) Czujka dymu
US20240078895A1 (en) Optical filter, and test assembly and method for smoke detector
JP6957273B2 (ja) 散乱光式感知器
JP4043204B2 (ja) 火災検知器
JP2021522523A (ja) 散乱放射式光学煙検出器
CN111080960A (zh) 一种带有导光散射结构的烟感探测装置
JP3236708B2 (ja) 散乱光式煙感知器
CN110940619A (zh) 一种高精准烟雾探测器
JP5038112B2 (ja) 光電式煙感知器
CN217386468U (zh) 光电感烟探测器
JP7338956B2 (ja) 火災検出装置
CN209357202U (zh) 感烟火灾探测报警器
CN217386469U (zh) 一种烟雾报警器
US20080304067A1 (en) Smoke detector
JP2020067920A (ja) 煙感知器
JP7208731B2 (ja) 火災検出装置
JP3389227B2 (ja) 散乱光式煙感知器

Legal Events

Date Code Title Description
STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION